The linguistic style of many schizophrenics is a distinctive feature of their clinical picture, but the cognitive processes underlying the way in which this patient group uses language remain unclear. Semantic processing in normal individuals appears to involve at least two types of information processing: (a) processes that are automatic and rapid; and (b) processes that are controlled by the individual and require more time to engage. The locus of disturbance in the semantic processing of schizophrenics is currently unknown. The proposed study is designed to address two questions: (1) the locus of potential disturbance in schizophrenics' semantic processing (automatic versus controlled processes); and (2) the time-locked characteristics of schizophrenics semantic processing that occur after stimulus presentation and prior to response output (e.g., lever press). Psychophysiological (event-related potentials) and behavioral (reaction time) responses during the performance of a lexical decision task will be examined in 20 schizophrenic patients and 20 normal controls. Event-related potentials (ERP's) provide information not accessible with behavioral data (reaction time) by providing time-locked indicators of cognitive events that occur between stimulus presentation and response output. We hypothesize that schizophrenic patients will be characterized by disturbances in controlled semantic processing, but that they may exhibit normal automatic semantic processing. In addition, exploratory analyses will be conducted concerning the association of semantic processing and: (1) thought disorder; and (2) medication status.